The invention relates generally to methods and devices for automatic visual perception, and more particularly to methods and devices for processing image signals using one or more self-adapting histogram calculation units capable of implementing anticipation and learning modes. Such devices can be termed an electronic spatio-temporal neuron, and is particularly useful for image processing, but may also be used for processing of any other signals, such as sound signals.
Image processing methods and devices are already known, which enable real-time recognition, localization and/or extraction of objects corresponding to certain criteria of their context. The selection criteria can be extremely varied. They may be related to speed, shape, color . . . or a combination of these criteria. These methods and devices can be used to facilitate the acquisition of a scene or of a phenomenon by an observer or to control an automatism on the basis of information thus extracted. Such methods and devices are for example described in the following publications FR-2.611063 and WO-98/05002.
Certain of these methods and devices implement a spatial and temporal processing unit that, upon receiving a video-type signal S(PI), produces a number of parameters for each pixel. It may be, for instance speed V, direction DL, a time constant CO and a binary enabling parameter VL in addition to the delayed video signal VR and the different frame, line and pixel synchronization signals gathered under the denomination F.
In such devices, the importance of constituting histograms of these parameters and using them in a visual perception processor has already been outlined in order to acquire, manipulate and process statistical information.
The purpose of such a visual perception processor includes outputting a signal S'(t) that carries for each pixel a significant piece of information of the result obtained when applying recognition or selection criteria. These criteria are predefined or prepared by the image processing methods and devices properly speaking.
Such a method and such a device, in particular, are divulged in the patent application WO-98/05002, already mentioned, that has been integrated thereto for reference purposes.
It is therefore desirable to provide an improved visual perception processor, and methods, as well as, in preferred embodiments, the auto-adapting, anticipation and learning functions.